Field of the Invention
The present invention relates generally to GNSS/INS systems and more particularly to GNSS/INS systems utilized for heavy equipment navigation and working edge positioning.
Background Information
Heavy equipment vehicles typically have one or more working edges (e.g., blades) that are utilized to perform specific functions. Examples of heavy equipment includes, e.g., bulldozers, graders, front end loaders, back hoes, etc. As used herein, the term working edge refers generally to any component of heavy equipment that performs a specific function in which precise positioning may be necessary. Examples of working edges may include the blade of a bulldozer or grader, the scoop of a backhoe, etc.
During normal operation, the driver of the heavy equipment will utilize the working edge to perform some function, e.g., using the blade of a bulldozer to level a section of land to a predetermined grade. The work is typically checked manually during operation to ensure that it has been completed in accordance with a pre-defined specification. For example, a bulldozer operator may level the section of land, but separate checks are needed to verify that it is at the desired grade, width, etc. This may result in an iterative process of performing work and then taking measurements, with the measurements being used for the next round of work until the desired outcome has been achieved. That is, the heavy equipment may perform an operation, e.g., grade a section of land. After grading, a team of surveyors and/or engineers must then manually verify that the grade correct, etc. If there are errors, then the heavy equipment must perform a second pass before a second set of measurements are taken, etc.
Recently, various manufacturers have produced automatic working edge positioning systems for use with heavy equipment machinery. Automatic working edge positioning systems are designed to enable productivity gains by precisely guiding the operator while working. Generally, an automatic working edge positioning system controls the positioning of the working edge during operation so that the desired work is performed in an automated manner. This typically results in a reduction in the number of work-measurements iterations required to complete a project. By automating working edge positioning, productivity is typically increased by reducing the number of work stoppages for surveying, etc. Instead, with an automated working edge positioning system, work may be conducted in a more efficient manner.
In a conventional heavy equipment working edge control system, one or more sensors are affixed to the working edge to monitor its location and/or orientation with respect to a fixed point of the heavy equipment vehicle. Illustratively, this working edge position information is relayed, via one or more cables, to a control system that is located within the cab of the vehicle. Typically, the heavy equipment vehicle will include a global navigation satellite system (GNSS) that provides accurate location of the machine. This location information, in conjunction with the relayed blade position, is utilized by the working edge control system to accurately grade and/or level the workspace.
One noted a disadvantage of conventional heavy equipment working edge control systems is that the delicate sensors are mounted on the working edge and are therefore subject to being damaged during normal operation of the machine. This increased chance of damage is the result of being located in a very stressful work environment. As will be appreciated by one skilled in the art, the working edge of a heavy equipment machine undergoes numerous stresses during operation. These stresses may be the result of dirt or other material striking the sensors, thereby damaging them or knocking them out of alignment and/or calibration.
The damage of sensors due to the stressful work environment in which they are located reduces the effectiveness of automatic working edge control systems. In response to the damage of a sensor, work must be stopped and the sensor replaced and/or repaired. Thus, the expected reduction of inefficiencies through the use of an automated working edge control system are lost due to the down time spent in repairing/replacing sensors.